The Screw,flat,4x12 is the lowest priced item on this Fr. Brake Master Cylinder schematic.
The Fr. Brake Master Cylinder assembly is constructed from several parts from which the M/c Sub Assy,fr B is the most expensive.
Some items from this specific schematic: Bolt,handle Lever, Stay Comp.,l.fr.b, Boot Comp., Bolt,flange,6x12.